C5

Measurement of the radiative properties of solid fuel particles in oxy-fuel atmospheres

In this project, the optical properties of burning solid fuel particles are investigated experimentally. Due to the high temperature level of Oxy-Fuel combustion, heat transfer is dominated by radiation. The emissivity is one of the key-parameters to determine the heat transfer between particles and their surroundings, which strongly affects the thermal balance in Oxy-Fuel boilers. Inside furnaces, the particle phase scatters thermal radiation, which affects the spatial radiation intensity and, thus, the temperature field in the furnace. Scattering properties of burning biomass in Oxy-Fuel atmospheres are hardly known, which is a gap to be closed by this project.

After having developed test rigs to measure the optical properties of burning particles in-flight, measurements will be carried out to produce a database and derive profound knowledge on different influential parameters on the optical properties of pulverized biomass particles. Measurement probes for the combustion facilities with increased size in the CRC 129 will be used to determine the radiative fields in these reactors. This will add data on a larger scale which is necessary to derive deep understanding of the effects and to compare numerical modelling results,

Parameters which will be tested for their influence on the optical parameters are:

• Fuel provenience
• Mineral content
• Combustion conditions (temperature, particle size, atmosphere)